Refrigerant mixture comprising difluromethane, pentafluroethane and 1,1,1-trifluoroethane

ABSTRACT

A novel refrigerant composition useful as a substitute for HCFC-22, comprising a first constituent of difluoromethane (CH 2 F 2 , HFC-32); a second constituent of pentafluoroethane (CHF 2 CF 3 , HFC-125); a third constituent of 1,1,1-trifluoroethane (CH 3 CF 3 , HFC-143a); a fourth constituent selected from the group consisting of cyclopropane (C 3 H 6 , RC-270), 1,1,1,2,3,3,3-heptafluoropropane (CF 3 CHFCF 3 , HFC-227ea), 1,1,1,2,2-pentafluoropropane (CH 3 CF 2 CF 3 , HFC-245cb), isobutane (CH(CH 3 ) 2 CH 3 , R-600a), octafluorocyclobutane (C 4 F 8 , RC-318), 1,1,1,2,3,3-hexafluoropropane (CHF 2 CHFCF 3 , HFC-236ea), butane (C 4 H 10 , R-600), bis(difluoromethyl)ether (CHF 2 OCHF 2 , HFE-134) and pentafluoroethylmethylether (CF 3 CF 2 OCH 3 , HFE-245).

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a refrigerant mixture which isuseful as a substitute for chlorodifluoromethane (CHCIF₂, HCFC-22). Moreparticularly, the present invention relates to a refrigerant compositionwhich is useful as a substitute for HCFC-22, which comprises a firstconstituent of difluoromethane (CH₂F₂, HFC-32); a second constituent ofpentafluoroethane (CHF₂CF₃, HFC-125); a third constituent of1,1,1-trifluoroethane (CH₃CF₃, HFC-143a); a fourth constituent selectedfrom the group consisting of cyclopropane (C₃H₆, RC-270),1,1,1,2,3,3,3-heptafluoropropane (CF₃CHFCF₃, HFC-227ea),1,1,1,2,2-pentafluoropropane (CH₃CF₂CF₃, HFC-245cb), isobutane(CH(CH₃)₂CH₃, R-600a), octafluorocyclobutane (C₄F₈, RC-318),1,1,1,2,3,3-hexafluoropropane (CHF₂CHFCF₃, HFC-236ea), butane (C₄H₁₀,R-600), bis(difluoromethyl)ether (CHF₂OCHF₂, HFE-134) andpentafluoroethylmethylether (CF₃CF₂OCH₃, HFE-245).

[0003] 2. Description of the Background Art

[0004] As is well known, CFC compounds have been restricted inproduciton and use in accordance with the Montreal Protocol because theyhave been found as a main factor in contributing to the destruction ofthe ozone layer. In advanced nations, the use of such CFC compounds hasalready been banned since 1996. It is also known that HCFC-basedcompounds such as HCFC-22 have considerable effects in causing damage tothe ozone layer even though this effect is less severe than those of theCFC compounds. For this reason, a restriction has been made to graduallyreduce the use of such HCFC-based compounds. A plan has also been madeto ban the use of HCFC-based compounds about the year 2020.

[0005] This has resulted in a number of world-wide research efforts toproduce substitute materials coping with the restriction in use ofHCFC-22 which will be more severe in the future. The representativeexamples of a substitute refrigerant mixtures are HFC-407C and HFC410Aproposed by the American Society of Heating. Refrigerating andAir-Conditioning Engineers (ASHRAE). HFC407C is a refrigerant mixture ofHFC-32/125/134a in a ratio of 23/25/52 (based on weight percent).Meanwhile, HFC-410A is a refrigerant mixture of HFC-32/125 in a ratio of50/50 (based on weight percent).

[0006] In addition, U.S. Pat. No. 5,080,823 discloses a mixedrefrigerant composition of HFC-143a/opropane (C₃H₈), U.S. Pat. No.5,185,094: HFC-32/125/134a, U.S. Pat. No. 5,211,867: HFC-125/143a, U.S.Pat. No. 5,234,613: HFC-32/propane, U.S. Pat. No. 5,236,611:PFC-218/HFC-143a, U.S. Pat. No. 5,290,466: HFC-32/134a/134, U.S. Pat.No. 5,340,490: HFC-23/CO₂ or HFC-23/116/CO₂, U.S. Pat. No. 5,403,504:HFC-125/32, U.S. Pat. No. 5,429,760: HFC-23/134a, U.S. Pat. No.5,538,660: HFC-32/HFC-134a/FC-14 or HFC-32/HFC-134a/PFC-218, and U.S.Pat. No. 5,643,492: HFC-32/125/134a.

[0007] Also, Japanese Patent Laid-open Publication No. 172386/1991discloses a mixed refrigerant composition of HFC-32/125/152, JapanesePatent Laid-open Publication No. 170594/1991: HFC-23/125/134a, JapanesePatent Laid-open Publication No. 170592/1991: HFC-32/143a/152a, JapanesePatent Laid-open Publication No. 170593/1991: HFC-23/125/32, JapanesePatent Laid-open Publication No. 170591/1991: HFC-23/143a/134a, JapanesePatent Laid-open Publication No. 170590/1991: HFC-125/134a/32, JapanesePatent Laid-open Publication No. 170589/1991: HFC-23/143a/152a, JapanesePatent Laid-open Publication No. 170588/1991: HFC-125/143a/134a,Japanese Patent Laid-open Publication No. 170587/1991: HFC-32/134a/152a,Japanese Patent Laid-open Publication No. 170586/1991: HFC-32/143a/134a,Japanese Patent Laid-open Publication No. 170585/1991: HFC-32/125/134a,Japanese Patent Laid-open Publication No. 170584/1991: HFC-23/134a/152a,Japanese Patent Laid-open Publication No. 170583/1991: HFC-125/143a/32,Japanese Patent Laid-open Publication No. 222893/1992: HFC-32/125,Japanese Patent Laid-open Publication No. 154887/1992: HFC-134/152a,Japanese Patent Laid-open Publication No. 117645/1993:HFC-23/134a/propane, Japanese Patent Laid-open Publication No.117643/1993: HFC-125/134a/propane, Japanese Patent Laid-open PublicationNo. 65561/1994: HFC-23/152a/PFC-218, Japanese Patent Laid-OpenPublication No. 128872/1994: HFC-32/PFC-218, Japanese Patent Laid-OpenPublication No. 220433/1994: HFC-32/125RC-318, Japanese Patent Laid-OpenPublication No. 173462/1995: HFC-143a/125/134a/heptane (C₇H₁₆), JapanesePatent Laid-open Publication No. 176537/1996: PFC-218/RC-270/HFC-152a,Japanese Patent Laid-open Publication No. 151569/1996:propane/RC-270/HFC-34a, Japanese Patent Laid-open Publication No.127767/1996: HFC-32/134a/RC-318, Japanese Patent Laid-open PublicationNo. 25480/1997: HFC-32/134a/125/isobutane, Japanese Patent Laid-openPublication No. 59611/1997: HFC-134a/isobutane, Japanese PatentLaid-Open Publication No. 208941/1997: HFC-32/152a/125/RC-270, andJapanese Patent Laid-open Publication No. 221664/1997:HFC-125/143a/134a/RC-270.

[0008] Also, Korean Patent Publication No. 93-10514 (Application No.90-19594) discloses a mixed refrigerant composition of HFC-23/132/152a,HFC-23/125/152a, HFC-32/143a/152a, HFC-125/143a/152a, HFC-32/125/125a,HFC-23/143a/152a, or HFC-23/125/152a, Korean Patent Publication No.93-10515 (Application No. 90-19596): HFC-23/32/134, HFC-23/32/134a,HFC-23/125/134a, HFC-23/125/134, HFC-32/125/134, HFC-23/143a/134a,HFC-32/125/134a, HFC-125/143a/134a, or HFC-125/143a/134, Korean PatentLaid-Open Publication No. 96-4485 (Application No. 95-21221):HFC-32/23/134a, Korean patent Laid-open Publication No. 95-704438(Application No. 95-701865): HFC-32/125/134a, Korean patent Laid-openPublication No. 96-701168 (Application No. 95-704038):HFC-227ea/HFC-152a, and Korean Patent Laid-open Publication No.97-704853 (Application No. 97-700436): HFC-134a/HCFC-124/butane.

SUMMARY OF THE INVENTION

[0009] Therefore, an object of the present invention is to provide anovel refrigerant mixture which is useful as a substitute for HCFC-22.That is, the present invention has an object to provide a refrigerantcomposition produced by mixing additionally one component of RC-270,HFC-227ea, HFC-245cb, R-600a, RC-318, HFC-236ea, R600, HFE-134 andHFE-245 with a mixture of HFC-32, HFC-125 and HFC-143a, therebyproducing a composition capable of exhibiting properties similar toHCFC-22.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention relates to a refrigerant composition whichis useful as a substitute for HCFC-22, which comprises a firstconstituent of difluoromethane (CH₂F₂, HFC-32); a second constituent ofpentafluoroethane (CHF₂CF₃, HFC-125); a third constituent of1,1,1-trifluoroethane (CH₃CF₃, HFC-143a); a fourth constituent selectedfrom the group consisting of cyclopropane (C₃H₆, RC-270),1,1,1,2,3,3,3-heptafluoropropane (CF₃CHFCF₃, HFC-227ea),1,1,1,2,2-pentafluoropropane (CH₃CF₂CF₃, HFC-245cb), isobutane(CH(CH₃)₂CH₃, R-600a), octafluorocyclobutane (C₄F₈, RC-318),1,1,1,2,3,3-hexafluoropropane (CHF₂CHFCF₃, HFC-236ea), butane (C₄H₁₀,R-600), bis(difluoromethyl)ether (CHF₂OCHF₂, HFE-134) andpentafluoroethylmethylether (CF₃CF₂OCH₃, HFE-245).

[0011] It is preferred that the refrigerant composition of the presentinvention comprises a first constituent of 15 to 95% by weightdifluoromethane (CH₂F₂, HFC-32); a second constituent of an amount up to60% by weight pentafluoroethane (CHF₂CF₃, HFC-125); a third constituentof an amount up to 70% by weight 1,1,1-trifluoroethane (CH₃CF₃,HFC-143a); a fourth constituent of an amount up to 50% by weightcomprising one selected from the group consisting of cyclopropane (C₃H₆,RC-270), 1,1,1,2,3,3,3-heptafluoropropane (CF₃CHFCF₃, HFC-227ea),1,1,1,2,2-pentafluoropropane (CH₃CF₂CF₃, HFC-245cb), isobutane(CH(CH₃)₂CH₃, R-600a), octafluorocyclobutane (,C₄F₈, RC-318),1,1,1,2,3,3-hexafluoropropane (CHF₂CHFCF₃, HFC-236ea), butane (C₄H₁₀,R-600), bis(difluoromethyl)ether (CHF₂OCHF₂, HFE-134) andpentafluoroethylmethylether (CF₃CF₂OCH₃, HFE-245).

[0012] In accordance with the present invention, the refrigerantcomposition as mentioned above is applied to a refrigeration systemwhich comprises a compressor, a condenser, an expansion valve, and anevaporator in order to evaluate the coefficient of performance (COP),the volumetric capacity of refrigereant (VC), and pressures in thecompressor and evaporator. The novel refrigerant mixture according tothe present invention is evaluated to be substantially equivalent toHFC-407C or HFC-410A in terms of performance. Accordingly, therefrigerant mixture of the present invention is useful as a substitutefor HCFC-22.

[0013] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and RC-270, the composition comprises15 to 60% by weight of HFC-32, an amount up to 50% by weight of HFC-125,20 to 70% by weight of HFC-143a and an amount up to 15% by weight ofRC-270, and preferably, the composition comprises 25 to 45% by weight ofHFC-32, 2 to 35% by weight of HFC-125, 28 to 60% by weight of HFC-143aand an amount up to 10% by weight of RC-270.

[0014] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and HFC-227a, the compositioncomprises 20 to 60% by weight of HFC-32, an amount up to 60% by weightof HFC-125, an amount up to 70% by weight of HFC-143a and an amount upto 50% by weight of HFC-227a, and preferably, the composition comprises28 to 50% by weight of HFC-32, 2 to 50% by weight of HFC-125, 5 to 60%by weight of HFC-143a and an amount up to 40% by weight of HFC-227ea.

[0015] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and HFC-245cb, the compositioncomprises 20 to 90% by weight of HFC-32, an amount up to 60% by weightof HFC-125, an amount up to 60% by weight of HFC-143a and an amount upto 50% by weight of HFC-245cb, and preferably, the composition comprises30 to 85% by weight of HFC-32, 2 to 45% by weight of HFC-125, 3 to 50%by weight of HFC-143a and an amount up to 40% by weight of HFC-245cb.

[0016] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and R600a, the composition comprises30-60% by weight of HFC-32, an amount up to 45% by weight of HFC-125, 15to 50% by weight of HFC-143a and an amount up to 20% by weight ofR-600a, and preferably, the composition comprises 38 to 50% by weight ofHFC-32, 5 to 35% by weight of HFC-125, 20 to 43% by weight of HFC-143aand an amount up to 15% by weight of R-600a.

[0017] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and RC-318, the composition comprises20 to 60% by is weight of HFC-32, an amount up to 45% by weight ofHFC-125, 10 to 50% by weight of HFC-143a and an amount up to 20% byweight of RC-318, and preferably, the composition comprises 30 to 48% byweight of HFC-32, 10 to 35% by weight of HFC-125, 20 to 40% by weight ofHFC-143a and an amount up to 15% by weight of RC-318.

[0018] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and HFC-236ea, the compositioncomprises 20 to 85% by weight of HFC-32, an amount up to 40% by weightof HFC-125, an amount up to 60% by weight of HFC-143a and an amount upto 30% by weight of HFC-236ea, and preferably, the composition comprises30 to 75% by weight of HFC-32, 5 to 30% by weight of HFC-125, 5 to 48%by weight of HFC-143a and an amount up to 20% by weight of HFC-236ea.

[0019] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and R600, the composition comprises25 to 70% by weight of HFC-32, an amount up to 60% by weight of HFC-125,an amount up to 40% by weight of HFC-143a and an amount up to 20% byweight of R-600, and preferably, the composition comprises 35 to 60% byweight of HFC-32, 5 to 50% by weight of HFC-125, 5 to 33% by weight ofHFC-143a and an amount up to 12% by weight of R-600.

[0020] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and HFE-134, the compositioncomprises 30 to 95% by weight of HFC-32, an amount up to 50% by weightof HFC-125, an amount up to 40% by weight of HFC-143a and an amount upto 15% by weight of HFE-134, and preferably, the composition comprises40 to 88% by weight of HFC-32, 2 to 40% by weight of HFC-125, 2 to 30%by weight of HFC-143a and an amount up to 10% by weight of HFE-134.

[0021] Where the refrigerant composition of the present inventionincludes HFC-32, HFC-125, HFC-143a and HFE-245, the compositioncomprises 30 to 90% by weight of HFC-32, an amount up to 50% by weightof HFC-125, an amount up to 45% by weight of HFC-143a and an amount upto 15% by weight of HFE-245, and preferably, the composition comprises40 to 85% by weight of HFC-32, 5 to 40% by weight of HFC-125, 5 to 38%by weight of HFC-143a and an amount up to 10% by weight of HFE-245.

[0022] The present invention will now be described in more detailreferring to the following examples. It is to be understood that theseexamples are merely illustrative and it is not intended to limit thescope of the present invention to these examples.

EXAMPLE

[0023] Evaluation of Performance of Refrigerant Composition

[0024] In order to evaluate the performance of the refrigerant mixtureaccording to the present invention, a refrigeration system including acompressor, a condenser, an expansion valve, and an evaporator was usedwhich has the following performance evaluation conditions:

[0025] Refrigeration capacity 2 kW

[0026] Overall Heat Transfer coefficient in evaporator (UA): 0.20 kW/K

[0027] Overall Heat Transfer coefficient in condenser (UA): 0.24 kW/K

[0028] Degree of subcooling in condenser: 5° C.

[0029] Degree of superheating in evaporator: 5° C.

[0030] Efficiency of compressor: 0.8

[0031] Temperature of secondary fluid at inlet of condenser: 25° C.

[0032] Temperature of secondary fluid at outlet of condenser: 35° C.

[0033] Temperature of secondary fluid at inlet of evaporator: 15° C.

[0034] Temperature of secondary fluid at outlet of evaporator: 5° C.

[0035] Under the above conditions, the refrigerant compositionsaccording to the present invention were compared to HCFC-22, HFC-407Cand HFC-410A in terms of the main factors for evaluating the refrigerantperformance, that is, the coefficient of performance (COP), thevolumetric capacity of refrigerant (VC), and evaporator pressure(P_(L)), and condenser pressure (P_(H)).

Comparative Examples 1 to 3

[0036] HCFC-22, HFC-407C and HFC-410A compared to the refrigerantcompositions of the present invention have the following evaluatedperformances. TABLE 1 Evaluated performance of HGFG-22, HFC-407C andHFC-410A Comparative HCFC-22 HFC-32 HFC-125 HFC-134a VC P_(L) P_(H)example No. refrigerant (wt %) (wt %) (wt %) (wt %) COP (kJ/m³) (kPa)(kPa) 1 HCFC-22 100 — — — 5.45 3338 455 1254 2 HFC-407C — 23 25 52 4.983412 460 1445 3 HFC-410A — 50 50 — 5.31 5117 730 1993

[0037] Referring to Table 1, it can be seen that HFC-407C exhibits a COPslightly less than that of HCFC-22 while exhibiting a VC and pressuressimilar to those of HCFC-22. On the other hand, HFC-410A has a COPsimilar to that of HCFC-22 while exhibiting pressures slightly higherthan those of HCFC-22. It should be noted that a composition exhibitinga refrigerant performance defined as above is useful as a substituterefrigerant for HCFC-22. Accordingly, the performances of therefrigerant mixtures according to the present invention were evaluatedand compared with the above evaluated results.

Example 1

[0038] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/RC-270

[0039] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/RC-270 at different weight percent of eachconstituents are described in Table 2, respectively. Referring to Table2, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant useful as a substitute forHCFC-22. TABLE 2 Evaluated performance of refrigerant mixture ofHFC-32/HFC-125/HFC-143a/RC-270 Composition HFC-32 HFC-125 HFC-143aRC-270 VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP (kJ/m³) (kPa)(kPa) 1 40 30 30 0 5.20 4797 701 1919 2 30 35 30 5 5.06 4702 714 1949 335 30 30 5 5.09 4820 726 1975 4 25 35 35 5 4.98 4548 698 1923 5 40 30 282 5.17 4868 718 1957 6 42 25 30 3 5.18 4929 728 1973 7 42 23 32 3 5.184922 728 1970 8 42 18 37 3 5.20 4910 726 1959 9 42 10 45 3 5.20 4889 7241948 10 42 5 50 3 5.20 4877 724 1942 11 42 0 55 3 5.20 4865 723 1937 1245 0 55 0 5.26 4814 702 1891 13 33 0 60 7 5.11 4759 726 1941 14 33 0 587 5.11 4761 727 1942 15 28 2 60 10 5.04 4677 725 1940

Example 2

[0040] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/HFC-227ea

[0041] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/HFC-227ea at different weight percent of eachconstituents are described in Table 3, respectively. Referring to Table3, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 3 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/HFC-277ea Composition HFC-32 HFC-125HFC-143a HFC-227ea VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 28 2 60 10 5.04 4322 644 1803 2 35 0 60 5 5.144554 673 1847 3 45 10 45 0 5.26 4841 705 1904 4 30 30 35 5 5.06 4493 6671865 5 30 40 28 2 5.06 4554 677 1891 6 40 5 50 5 5.20 4688 687 1875 7 3533 25 7 5.13 4631 679 1891 8 40 15 30 15 5.18 4642 674 1872 9 50 15 1520 5.26 4866 695 1917 10 45 20 10 25 5.17 4705 673 1897 11 50 20 0 305.22 4807 681 1918 12 48 7 5 40 5.09 4572 649 1875 13 35 45 12 8 5.114670 684 1919 14 40 50 7 3 5.18 4870 708 1962 15 40 5 50 3 5.20 4688 6871875

Example 3

[0042] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/HFC-245cb

[0043] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/HFC-245cb at different weight percent of eachconstituents are described in Table 4, respectively. Referring to Table4, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 4 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/HFC-245cb Composition HFC-32 HFC-125HFC-143a HFC-245cb VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 40 5 50 5 5.19 4633 676 1854 2 30 40 20 10 4.994360 641 1839 3 50 20 10 20 5.20 4630 652 1843 4 60 10 5 25 5.25 4720655 1847 5 70 2 13 15 5.41 5040 701 1899 6 80 2 3 15 5.47 5180 712 19177 85 0 0 15 5.51 5235 716 1916 8 45 30 15 10 5.22 4739 678 1886 9 45 458 2 5.24 4946 712 1959 10 55 8 30 7 5.35 4927 701 1895 11 50 10 40 05.31 4940 714 1919 12 60 5 5 30 5.21 4908 638 1822 13 50 6 4 40 5.034180 576 1732

Example 4

[0044] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/R-600a

[0045] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/R-600a at different weight percent of eachconstituents are described in Table 5, respectively. Referring to Table5, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 5 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/R-600a Composition HFC-32 HFC-125HFC-143a R-600a VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 40 20 30 10 5.08 4722 716 1947 2 45 10 40 5 5.204887 726 1953 3 40 30 30 0 5.20 4797 701 1919 4 38 35 20 7 5.10 4748 7141955 5 48 15 35 2 5.26 4951 723 1946 6 50 5 43 2 5.28 4963 724 1940 7 450 40 15 5.02 4673 714 1946

Example 5

[0046] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/RC-318

[0047] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/RC-318 at different weight percent of eachconstituents are described in Table 6, respectively. Referring to Table6, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 6 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/RC-318 Composition HFC-32 HFC-125HFC-143a RC-318 VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 35 30 25 10 5.11 4791 716 1970 2 45 20 30 5 5.234955 724 1967 3 48 10 40 2 5.28 4938 718 1933 4 30 15 40 15 5.00 4623705 1952 5 40 30 30 0 5.20 4797 701 1919 6 43 0 50 7 5.22 4883 721 19437 40 35 20 5 5.17 4890 719 1972

Example 6

[0048] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/HFC-236ea

[0049] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/HFC-236ea at different weight percent of eachconstituents are described in Table 7, respectively. Referring to Table7, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 7 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/HFC-236ea Composition HFC-32 HFC-125HFC-143a HFC-236ea VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 40 20 30 10 5.06 4487 646 1844 2 55 30 10 5 5.315076 722 1972 3 30 20 48 2 5.08 4467 663 1842 4 60 5 20 15 5.20 4781 6711884 5 70 10 0 20 5.13 4789 661 1899 6 35 18 40 7 5.08 4457 650 1832 775 0 5 20 5.22 4902 677 1904 8 50 25 25 0 5.31 4994 718 1941

Example 7

[0050] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/R-600

[0051] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/R-600 at different weight percent of eachconstituents are described in Table 8, respectively. Referring to Table8, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 8 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/R-600 Composition HFC-32 HFC-125HFC-143a RC-600 VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 40 25 30 5 5.14 4708 698 1911 2 50 20 20 10 5.094711 693 1920 3 55 10 33 2 5.34 5042 728 1945 4 53 15 25 7 5.28 4970 7261948 5 35 30 32 3 5.13 4635 689 1893 6 60 0 28 12 5.10 4797 705 1938 745 40 10 5 5.21 4886 715 1954 8 45 50 0 5 5.20 4920 717 1972 9 40 45 150 5.19 4859 708 1951

Example 8

[0052] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/HFE-134

[0053] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/HFE-134 at different weight percent of eachconstituents are described in Table 9, respectively. Referring to Table9, it can be found that the performance of the compositions indicated ineach item of Table 2 fall within the ranges between those of HFC407C andHFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 9 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/HFE-134 Composition HFC-32 HFC-125HFC-143a HFE-134 VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 70 20 5 5 5.21 4904 675 1904 2 80 10 2 8 5.09 4766647 1878 3 85 5 0 10 5.02 4665 629 1857 4 88 0 10 2 5.42 5248 721 1938 565 15 15 5 5.18 4815 669 1890 6 75 2 20 3 5.72 5054 702 1917 7 60 8 30 25.30 4950 700 1909 8 50 30 15 5 5.10 4619 649 1865 9 40 40 15 5 4.994440 632 1847 10 50 25 25 0 5.31 4994 718 1941

Example 9

[0054] Evaluation of Performance of Refrigerant Mixture ofHFC-32/HFC-125/HFC-143a/HFE-245

[0055] The evaluated performances of the refrigerant mixture comprisingHFC-32/HFC-125/HFC-143a/HFE-245 at different weight percent of eachconstituents are described in Table 10, respectively. Referring to Table10, it can be found that the performance of the compositions indicatedin each item of Table 2 fall within the ranges between those of HFC407Cand HFC-410A, so that the tested refrigerant mixture is useful as asubstitute for HCFC-22. TABLE 10 Evaluated performance of refrigerantmixture of HFC-32/HFC-125/HFC-143a/HFE-245 Composition HFC-32 HFC-125HFC-143a HFE-245 VC P_(L) P_(H) No. (wt %) (wt %) (wt %) (wt %) COP(kJ/m³) (kPa) (kPa) 1 40 40 15 5 5.03 4545 655 1881 2 80 5 5 10 5.104868 674 1921 3 70 10 12 8 5.24 4952 690 1920 4 60 0 38 2 5.37 5047 7191924 5 50 25 20 5 5.20 4795 683 1902 6 50 32 13 5 5.19 4807 683 1912 752 15 30 3 5.31 4921 703 1909 8 85 7 0 8 5.47 5289 725 1946 9 65 15 15 55.26 4980 707 1936 10 50 25 25 0 5.31 4994 718 1941

[0056] As apparent from the above description, the present inventionprovides a refrigerant composition, which is useful as a substitute forHCFC-22, produced by mixing additionally any one component of RC-270,HFC-227ea, HFC-245cb, R-600a, RC-318, HFC-236ea, R600, HFE-134 andHFE-245 with a mixture of HFC-32/HFC-125 and HFC-143a. The refrigerantcomposition according to the present invention has an advantage in thatit does not damage the ozone layer, so there is no possibility ofrestricted in use in the future. The above materials, which arecomponents of the refrigerant composition according to the presentinvention, are currently commercially available, or active research forthose materials is being conducted to make them commercially availablein the near future.

[0057] As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the meets and bounds of theclaims, or equivalence of such meets and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. A refrigerant composition useful as a substitutefor chlorodifluoromethane, comprising: a first constituent ofdifluoromethane; a second constituent of pentafluoroethane; a thirdconstituent of 1,1,1-trifluoroethane; a fourth constituent selected fromthe group consisting of cyclopropane, 1,1,1,2,3,3,3-heptafluoropropane,1,1,1,2,2-pentafluoropropane, isobutane, octafluorocyclobutane,1,1,1,2,3,3-hexafluoropropane, butane, bis(difluoromethyl)ether andpentafluoroethylmethylether.
 2. The refrigerant composition according toclaim 1, wherein the first constituent is 15 to 95 by weight, the secondconstituent is present in an amount up to 60% by weight, the thirdconstituent is present in an amount up to 70% by weight, and the fourthconstituent is present in an amount up to 50% by weight.
 3. Therefrigerant composition according to claim 1, wherein said compositioncomprises 25 to 45% by weight of difluoromethane, 2 to 35% by weight ofpentafluorethane, 28 to 60% by weight of 1,1,1-trifluoroethane and anamount up to 10% by weight of cyclopropane.
 4. The refrigerantcomposition according to claim 1, wherein said composition comprises 28to 50% by weight of difluoromethane, 2 to 50% by weight ofpentafluoroethane, 5 to 60% by weight of 1,1,1-trifluoroethane and anamount up to 40% by weight of 1,1,1,2,3,3,3-heptafluoropropane.
 5. Therefrigerant composition according to claim 1, wherein said compositioncomprises 30 to 85% by weight of difluoromethane, 2 to 45% by weight ofpentafluoroethane, 3 to 50% by weight of 1,1,1-trifluoroethane and anamount up to 40% by weight of 1,1,1,2,2-pentafluoropropane.
 6. Therefrigerant composition according to claim 1, wherein said compositioncomprises 38 to 50% by weight of difluoromethane, 5 to 35% by weight ofpentafluoroethane, 20 to 43% by weight of 1,1,1-trifluoroethane and anamount up to 15% by weight of isobutane.
 7. The refrigerant compositionaccording to claim 1, wherein said composition comprises 30 to 48% byweight of difluoromethane, 10 to 35% by weight of pentafluoroethane, 20to 40% by weight of 1,1,1-trifluoroethane and an amount up to 15% byweight of octafluorocyclobutane.
 8. The refrigerant compositionaccording to claim 1, wherein said composition comprises 30 to 75% byweight of difluoromethane, 5 to 30% by weight of pentafluoroethane, 5 to48% by weight of 1,1,1-trifluoroethane and an amount up to 20% by weightof 1,1,1,2,3,3-hexafluoropropane.
 9. The refrigerant compositionaccording to claim 1, wherein said composition comprises 35 to 60% byweight of difluoromethane, 5 to 50% by weight of pentafluoroethane, 5 to33% by weight of 1,1,1-trifluoroethane and an amount up to 12% by weightof butane.
 10. The refrigerant composition according to claim 1, whereinsaid composition comprises 40 to 88% by weight of difluoromethane, 2 to40% by weight of pentafluoroethane, 2 to 30% by weight of1,1,1-trifluoroethane and an amount up to 10% by weight ofbis(difluoromethyl)ether.
 11. The refrigerant composition according toclaim 1, wherein said composition comprises 40 to 85% by weight ofdifluoromethane, 5 to 40% by weight of pentafluoroethane, 5 to 38% byweight of 1,1,1-trifluoroethane and an amount up to 10% by weight ofpentanfluoroethylmethylether.